THE ELECTRIC ORGANS OF FISHES. 63 
nerves. The batteries were so powerful, that a shock from a 
large active fish was strong enough to strike down a man, and 
numb away his consciousness for several hours. The Torpedo 
was of special interest, because we were beginning to understand 
all the steps through which its organ had passed during its long 
and gradual evolution. Some of the species attained a great 
size. There was one, the Giant Torpedo, over four feet in 
length, which, when cast ashore at Cape Cod, was said often by 
its unexpected shocks to strike down the unwary fishermen 
when they attacked it with their harpoons and boathooks. The 
shock of the common British Torpedo was _ sufficiently 
strong to kill a duck, and when the organ was connected with a 
telephone the discharges first produced a croaking sound, but as 
the fish got excited each discharge was accompanied by a 
pronounced groan. The electricity discharged from the 
Torpedo’s batteries behaved like ordinary electricity, rendering 
the needle magnetic and emitting sparks, and it might even be ~ 
used in charging a Leyden jar. But it should be specially noted 
that the living battery of fishes differed from the ordinary 
batteries. A Leyden jar or a voltaic pile had no influence on 
the electricity it contained, while the electricity of the Torpedo 
was entirely under the control of its will, the Torpedo refusing 
to give a shock at one time, but readily discharging its batteries 
at another. What was perhaps still more remarkable, there were 
two large lobes in the brain of the Torpedo which regulated the 
production, storage, and discharge of the electricity. These 
electric lobes were composed of numerous giant nerve cells, 
from which numerous nerve fibres extended to pass direct to 
the batteries. When the electric lobes were destroyed, or the 
nerves passing from them were divided, the Torpedo was 
rendered as helpless as an engine without steam. 
Prof. Ewart then proceeded to describe the structure of the 
electric organ of the Torpedo, He stated that the battery 
consisted of an enormous number of columns or prisms—in the 
ordinary Torpedo from 400 to 500, in the American about 1000, 
making in the two batteries 2000 columns for storing electricity. 
In each of the 500 columns there were about 600 electric 
plates, so that in the ordinary Torpedo there might be about 
300,000 electric plates altogether, and in the Giant Torpedo, 
some 500,000. These plates were supplied with an enormous 
